Roller eccentric



v 1,568,290 G. s. MORISON I ROL ERECCENTRIc Jan. 5, 1926.

Fi led Augusi 2, 1923 IIIIIIIIIIIIIIIIIII' the following is PatentedJan. 5 1926.

enonen smrjn MOBISON, or-rrr'rsnnaen, PENNSYLVANIA.

' ROLLER ECCENTRIC.

Application filed August 2, 1923. Serial No. 655,376.

To all whom. it may concern:

Be it known that I, GEORGE SMITH Monr- SON, a subject of the King ofGreat Britain, and at present a resident of Pittsbur h, in the county ofAllegheny and State of Tennsylvania, have invented a new and usefulImprovement in Roller Eccentrics, of which a specification.

This invention relates to means for translating a rotary motion of onemember into an eccentric motion of another member. More articularly itrelates to the translation of motion from a rotar driven shaft to acircular member surroun ing the driven shaft and eccentrically movedthereby in relation thereto.

The objects of the invention comprise the translation of motion from arotary driving shaft having a normally fixed, axis to an eccentricallymovable surrounding member, without toothed gears, without slidingcontact surfaces, by means of true circular rollers in contactrespectively with the driving shaft and the eccentrically moving drivenmember, and adapted tobe revolved about t e driven shaft, thus producinga true roller eccentric. At the same time, by means of the resultingeccentric movement of he outer member or ring, or b means ofthe=revolu-' tion of the rollers a out the shaft, 'a very rapid rotationof the driving shaft may be translated into a comparatively slowreciprocating motion,,or into rotation of another member at a slowerspe'ed.- Other objects will be apparent to those familiar with the artfrom a consideration of the following drawings and specifications.

Referring to the drawings Fig. I shows an elevation and'partial sectlonof one embodiment of my invention, the roller eccentric bein a lied todrivin a vertically reg PE g ciprocating s aft; Fig. 2 is a partialvertical central section on-the line IIII of Fig. 1;

Fig; 3 is a partial vertical section on the line III'III of Fig. 4 of amodified form of the invention, showing the roller eccentric applied asthe pinion of an epicyclic gear arrangement, and driving also by way ofillustration a laterally extending shaft or arm; Fig. 4 is a partialcross line IV-IV of the device illustrated in Fig. 3, with additionalframe members shown; Fig. 5 is a diagrammatic. view of a modified formwherein rollers having two body portions of different diameters areused, this proximately diametricall section on the a view being asection on the line V-V of Fig. 6; and Fig. 6 is an .elevation andpartial section on the line VIVI of Fi 5.

Referring to Figs. 1 and 2, a sha 1 is mounted with suitable bearings ina frame 2- upon a base 3. This shaft, which will hereafter be referredto as the driving shaft, is

itself driven by' any suitable form of prime mover, as for example aturbine, electric motor, etc. Between the bearings the shaft carries twocollars 4 and 5, and in the space between these collars three cylindersor rollers, 6, 7 and 8, are spaced around the shaft, and bear uponthereto, as illustrated inFig. 1. The rollers 7 and 8 have central pins(or trunnions) 9, which are engaged by connecting links 10 on each side.1 The pins 9 may be fixed in the rollers, and rotatable in the link, orvice versa, it being necessary for the rollers to be free to rotate ontheir respective axes with respect to the link, the function of which issimply to maintain them in their relative spaced-apart position withrespect to each other. The two rollers 7 and 8 are preferably of'thesame size, while the roller 6 is preferably the largest of the three.The arrangement, however, may be reversed, and two large rollers and onesmall one used.

Surrounding the three rollers 6, 7 and 8,

is a ring member 11, having a' circular it in parallel axial relationrollers-constantly bearing against it at some pgi'nt of their periphery,the three rollers ing positively spaced apart, and an outer ring bearingupon the outer peripheries of the three rollers at points respectivelyapopposite the points of contact of the rol ers with the drivmg shaft,and one of the rollers being larger than the other two, positively callywith respect to the driving shaft 1.

The eccentric mounting of the ring with respect to the driving shaftproducesa space between the face of the groove 12 and the periphery ofthe driving shaft 1 which space is widest at one point, and decreases inwidth in opposite circumferential directions or vice "versa, results inpositlonmg the ring 11 eccentri i of the shaft, in

from the widest point. For example, referring to Fig. '1, the spacebetween the shaft 1 and the face of groove 12 is widest on the line ofcenters of the shaft and ring, on the upper side of the driving shaft,on that portion of the line marked X; and narrowest on the lower portionof the line of centers, marked Y, diametrically opposite on the otherside of the shaft. The space between the periphery of the shaft and theinner face of the ring gradually symmetrically and uniformly narrowsfrom the widest point X as measured on any exten sion of a radius ofshaft 1, as such a radial line is revolved in either direction aroundthe center of the shaft 1 from coincidence with the portion of the lineof center marked X to coincidence with the portion thereof marked Y. Thelarger roller 6 is adapted' to be positioned approximately at the pointof greatest width of the space between 1 and 12, as illustrated inFig.1, and movement of the roller 6 in either direction, in that space,without movement of the ring 11, has a wedge-like effect, and results ina compression of the roller 6 between the driving shaft and outer ring.

Attached to the outer periphery of the ring 11 is a ri 'd arm 13,connected by a pin 14 to a heel crank lever 15, attached by a pin 16 toan extension 17 from the frame. Beyond the pin 14 the lever has a freearm 18, to the end of which by a pin 19 may be attached a vertical shaftor link 20, as illustrated in Fig. 1.

The operation of this embodiment of my invention is as follows: Thedriving shaft 1 being suitably driven in clockwise direction, referringto Fig. 1, causes the rollers 6, 7 and 8 to rotate in counter-clockwisedirection on their own axes, and they being free to move, revolve orroll about the shaft 1 on the track 12, in the direction of rotation thesame spaced relation relative to each other, all three revolving aboutthe driving shaft 1 as a center, in clockwise direction.

The outer peripheries of the rollers are in contact with the inner face12 of the ring 11, but as the ring 11 can not rotate with respect to itscenter, in consequence of its being held against any such movement bymeans of the attached arm 13, the result is that the rollers 6, 7, and 8revolve around the driving shaft 1, simply rolling upon the innerperiphery of the ring 11. In elfect they simply roll around the drivingshaft in the direction of its rotation fast enough to prevent a slippingcontact therewith, and on the ring 11 as a track, all r'olling membersrotating on their own axes at exactly the same peripheral speed.

The travel of the rollers of different sizes about shaft 1 imparts tothe ring 11 an eccentric movement. The path of travel of the center ofthe ring 11, or of any point thereon will be a circle with a radiusequal to the distance from the axis of the driving shaft 1 to the centerof the ring 11, this distance being constant. The center of the ring 11(i. e. of the path 12 therein) and the axes of rollers 6, 7 and8.revolve about the axis of shaft 1 in concentric circles.

Obviously. this resultant eccentric movement of the ring 11 may beutilized in various ways for imparting motion, including an epicyclicmotion, to various mechanisms. For example in Fig. 1 the arm 13 carriedby the ring 11 is applied to the lever 15, fulcrumed at 16, and attachedat its free end to a shaft 20, which it is desired to reciprocate. Whenthe shaft 1 is driven clockwise it tends to drive the roller 6 into thenarrowing or wedge-like space at the right of the vertical line ofcenter X of the arrangement shown in Fig. 1. There is produced awedge-like gripping of the large roller 6 between the driving shaft 1and the inner periphery 12 of the ring 11. The ring being freelysuspended with reference to the shaft 1, this gripping pressure isimmediately translated in equal degree also to the smaller rollers 7 and8. The resulting pressure is such that I have found that theshaft doesnot slip in contact with the rollers, or the rollers in contact with thering, in spite of the fact that the rollers run in an oil bath, but theshaft imparts a true rolling movement to the rollers which causes themand the ring 11 to revolve about it without lost motion. Even if therollers are not an absolutely accurate fit, as for example, if they havebecome slightly worn, the above described result follows, because thelarger roller merely moves slightly further into the tapered spaceprovided for it, and then automatically wedges, transferring pressure inequal proportion to the other two rollers, exactly as in the case wherethe three rollers are. of maximum size to fit within the space in therelation illustrated. In Figs. 3 and 4 I have illustrated a modificationin that instead of three rollers I use 4. These are preferably arrangedin two pairs of rollers of the same size in each pair, but of differentsize as compared to the other pair, as for example, two larger rollers6, and two smaller rollers 7 and 8. The two smaller rollers 7 and 8 areconnected by a link 25, and the two larger rollers 6 by a link 26, theroller being free to rotate with respect to the said link, as are therollers 7 and 8 with respect to the link 10 of Fig. 1. In thismodification it will be apparent that the two large rollers (Pare notpositioned at the maximum width of the space between the driving shaft 1and the ring 11, but are at approximately equal distances from the lineof maximum width, one on each side of that line, and are positivelyconnected together and spaced apart to maintain their respectiveositions.

The wor ing of this arrangement is not different in principle fromthatabove described with reference to Fig. 1. When the shaft 1 is drivenclockwise the roller 6* at the right is gripped between the shaft andthe surrounding ring 11. The resulting pressure is translated insubstantially equal degree from the gripped roller 6 to the rollers 7and 8, and there is in effect a three-point gripping and drive,resulting in the imparting of an eccentric movement to the ring 11 asthe rollers run around the rotating shaft 1, as will'be obvious. If therotary direction of the shaft 1 is reversed the roller 6 at the leftwill be gripped, the rollers will rotate and travel in the otherdirection with the shaft and consequently the ring 11 will be movedeceentrically by the gripped roller and the two smaller rollers, exactlyas in the other case. One of the large rollers therefore is in positionto be gripped (and consequently the other rollers 7 and 8" are equallgripped) upon rotation of the driving s aft in either direction. I

In connection with Figs. 3 and 4 I have illustratedv a different andalternative way of translating the eccentric movement of riphery oresulting gear or pinion with another ring the ring 11 to 'powerpurposes. This consists in applying teeth 30 to the outer pethe ring11', and surrounding the 31, having internalteeth 32 of the same pitch,and of atleast two teeth greater in' number. The eccentric movement ofthe ring 11 will thus drive the outer ring 31, whichis mounted onbearings 33 carried by shaft 1, causing it to rotate on a true geometricaxis,--i.- "e. the axis of shaft 1.- Power may be derived from thedriven rotating ring 31 by any suitable means, as for example it may beused to drive a belt, or

may ave frictional contact with additional rolls, or teeth may 'beprovided on the outer face of the ring 31, to drive other gears meshingtherewith. a

In connection" with Fig. 3, I have also illustrated a rigid arm 13'carried by the ring 11 which may be used for driving any desiredmachinerypas illustrated and described in connection with Fig. 1, above.In that case, however, some other means must be used for preventin freerotation of the eccentrically driven ring 11.. Otherwise it would notnecessarily drive a surrounding member, such as ring 31 of Fig. 3, butmight itself rotate on its own axis sufiiciently to accommodate themeshing of'teeth resulting from the epicyclic movement of theeccentrically driven ring. I have used the word free in connection withpermissive rotation of the eccentrically moving ring fixed axis, beprevented from all rotation.

It is only necessary that the eccentrically moving ring be sufficientlyfulcrumed against free rotation to insure a driving ac;- tion on theouter ring of fixed axis by reason of the meshing of the teeth of thetwo rings. That is to say, referring to Fig. 3, it is necessary toinsure-rotation of" ring 31 rather than rotation of ring 11. 'But to .dothis there may still be some rotation of ring 11, as will be obvious. Inone e1nbodiment of this invention which I have built, the teeth of ringengaging the teeth of a rotatable ring corresponding to 31, also engagecorresponding teeth of a third ring positioned besidering 31, but heldin fixed ment results in a xed amount of forced rotation of ring 11, asit travels in epicyclic movement about the inner periphery of the fixedouter ring, while at the .same timedriving the rotatable outer ring bythe epicyclic movement and meshing of .the teeth of the two movablerings.

It will be understood that the ep'icyclic gear arrangement illustratedin Fig. 3 may be applied to the ring 11 of Figs. 1 and 2, thearm 13being omitted, if desired.

Referring to Figs. 5 and 6 the modification illustrated comprises .adriving shaft 1", in contact with three rollers 6 7" and 8 each of whichhas three body portions, two outer portions being of the same andIposition. Such arrange- 11 in addition tolarger diameter than anintermediate cylindrical' body portion. In effect, there are two rollersu on one axis. The smaller intermediate diameters of these rollers areadapted to bear upon the inner face 12* of the ring 11", and the largerdiameters to middle portions of the rollers, and the body portions oflarger diameters being arranged ateach end of each roller, so as to formin effect retaining flanges on each side of the ring 11 Power may bederived by attaching a rigid arm 13" to the eccentrically driven ring11", as will be readily understood, and this moving arm may beused forthe driving of any desired mechanism as above described. Y

It will be apparent that in each of the forms illustrated, there may besecured a very substantial speed reduction. For example, referring toFig. 1, supposing the driving shaft 1 to be ten inches mcircumference inthe path of the rollers, and the inner face 12 of the ring 11 upon whichthe outer portions ofthe rollers bear to be .to drive associatedapparatus.

n n l n eighty inches in circumference, there wlll be one complete cycleof eccentric movement of Y the ring 11 for each nine revolutions of thedriving shaft. By varying. the comparative dimensions of the drivingshaft, rollers and ring, the speedreduction may be varied within aconsiderable range. By applying the roller eccentric as a pinion todrive an epicyclic gear, as shown in Fig. 3,01 by using the two-diameterrollers as shown in Figs. 5 and 6, a .much greater reduction may beattained. I have constructed successful machines having a reduction of17000 to 1.

Since as above pointed out, the rollers are caused to revolve about thedriving shaft when that member is rotated, a suitable axially alignedassociated shaft, or other rotatable element, may be driven in thesamedirection but at a lower speed by direct at tachment to the link 10 ofFig. 1, the links 25 and 26 of Fig. 3 or the link 10 of Fig. 5. I havenot attempted to illustrate or de scribe in this application all of themany applications and modifications that may be made of this invention.I have illustrated three arrangements for imparting an eccentric motionto a ring, from a rotating driving shaft by means of rolling members ofdifferent diameters positioned between the driving and driven member.Incidentally I have illustrated two ways of utilizing resultingeccentric movement of the ring I have also pointed out that therevolutions of the rollers between the driving shaft and eccentricallydriven ring may be utilized for direct rotation of associated mechanism,and particularly shafts or other rotary members having a common axiswith the driving shaft. I believe I am the first to make such anarrangement of mechanical elements, and therefore am entitled to broadpatent protection upon it, regardless of the use that may be made of themovement produced. i a r Although I have illustrated and described trulycylindrical rollers for furnishing the contact between the driving shaftand driven ring, I may, in certain cases, substitute spheres forcylinders. In the case of spheres, instead of linking them together withpins as illustrated in the case of rollers, which however may be doneeven with spheres or balls, I prefer to use connecting cages, similar tothose now known in connection with ball bearings. The linkingarrangement illustrated may be varied, as for example in Fi 1 the largerand one of the smaller rollers may be linked together and the otherallowed to run free,'

and in Fig. 3 a larger and a smaller roller on each side may belinked,-instead of the two larger and'two smaller.

I prefer to enclose the rollers and driving shaft in a casing so thatthe rollers may have a constant oil bath. This does not recular rollingmembers being of different rcspectlve diameters.

2. Mechanism for producing an eccentric motion of a ring membercomprising a circular rotatably driving shaft, an internally circularring surrounding said shaft and held against free rotation, circularrolling members positioned between the shaft and ring and bearingagainst the shaft and ring,

two of said circular rolling members being respectively of differentdiameters, and a rigid connection between two of the sald c1rcularrolling members.

3. A roller eccentric comprising a circular rotary driving shaft, aninternally circular ring surrounding said shaft and held against freerotation, a series of circular rolling members comprising at least twoof different respective diameters arranged in the space between saidshaft and ring, each of said circular rolling members being in contactwith the shaft and ring and positively spaced apart from every otherrolling member.

4. A roller eccentric comprisinga circular rotary driving shaft, aninternally circular ring surrounding said shaft, circular rollingmembers arranged in the space between said shaft and circular ring andin contact with said shaft and ring, two of said rollers being ofdifferent respective diameters, links connecting two of said circularrollingmembers and maintaining their spaced relation, and meanspreventing free rotation of the rin 5. A roller eccentric comprising acircular rotary driving shaft, an internally circular ring surroundingsaid shaft, circular rolling members arranged in the space between saidshaft and circular ring and in contact therewith, two of said rollersbeing of different respective diameters, means preventing free rotationof the ring, and means to apply the eccentric movement of the ring todrive connected mechanisms.

6. Mechanism for producing an eccentric motion, comprising a rotatablymounted driving shaft having a fixed axis, circular rolling membersarranged around and in contact with the driving shaft, one roller beingof greater diameter than one of the other rollers, two of the circularrolling members being positively spaced apart by :1. connecting member.a circular ring surrounding the rolling members and driving shaft andhaving, its inner circular periphery bearing against the outerperipheries offthe' said rollers, the ring being free to moveeccentrically but held against free rotation.

7. A power-translating device comprising a circular rotatable drivingshaft, a circular ring surrounding said shaft, a series of circularrolling members positioned between the shaft and the ring and bearingagainst said shaft and ring, the rolling members'being adapted torevolve about the shaft, some of the rolling members being ofdifferent-respective diameters.

8. A power-translating mechanism comprising a circular rotatable drivingshaft, a circular ri g surrounding the driving shaft, a series ofcircular rolling members adapted to revolve about the shaft andpositioned between and in contact with the driving shaft and interiorface of the ring, two of said circular inembers being of differentrespective diameters, and gear'teeth on the outer face of the ringwhereby to engage and drive associated apparatus by epicyclic movementof said ring.

'9. A power-translating mechanism comprising a circular rotatabledriving shaft, a circular ring surrounding the driving shaft, circularrolling members adapted to revolve about the shaft and positionedbetween and in contact with the driving shaft and interior face of thering, some of said circular members being of different respectivediameters, and means to engage and drive associated apparatus byeccentric movement of said ring.

10. A power-translating mechanism comprising a circular rotatable"driving shaft, :1 circular-ring surrounding the driving shaft, circularrolling members adapted to. revolve about the shaft and positionedbetween and in contact with the driving shaft and interior face of therin some of said circular members being of iiferent respective diameters, and means to engage and drive associated apparatus byrevolution of said circular rolling members.

11. A power-translating device comprism a circular rotatable drivingshaft, a circu ar ring surrounding said shaft, 0. series of circularrolling members positioned between the shaft and the ring and bearingagainst said shaft and ring, the rolling members being adapted torevolve about the shaft, some of the rolling members being of differentrespective diameters, and a member connecting two of the circularrolling members.

12. A device for translating power, comprising a circular rotary drivingshaft, a circular ring surrounding the shaft, circular roller memberspositioned between the shaft and inner circular periphery of the ringhearing against said shaft and ring and adapted to revolve about theshaft, some of said roller members being of different respectivediameters, means to prevent free rotation of a second ring surroundingthe first ring having a fixed axis and having teeth on its innercircular periphery adapted to mesh with and be engaged by the teeth ofthe inner ring, there being a greater number of teeth on the the ring,teeth on the outer face of the ring,

inner periphery of the outer ring than on i the inner ring, whereby theouter ring may be rotated by eccentric epicyclic movement of the innerring. i

I "13'. Power-translating mechanism comprising a circular rotary drivingshaft of fixed axis, a circularring surrounding the shaft, circularroller members positionedbetween and bearing against the shaft and ringand adapted to revolve about the shaft, some of the rollers being ofdifferent respective diameters, means to hold the ring against freerotation, and a member attached to a pair of said rollers and adapted tobe driven around the axis of said shaft by'revolution of said rollers.

14. A power translating device comprising an inner circular member, aninternallycircular ring member surrounding the inner member andeccentrically positioned with respect thereto, a series of intermediaterolling members positioned between and engaging said inner member andringand adapted to revolve about the inner member, certain ones ofsaidroller members being of different respective diameters.

In testimony whereof, I sign my name.

GEORGE SMITH MORISQN.

